Stress is a significant factor that can precipitate, exacerbate, and maintain psychopathology. The corticotropin-releasing factor (CRF) system has been implicated in mediating the stress response and linking it to psychopathology. Over-activity of the CRF system is implicated in depression, anxiety, and perhaps other stress-related disorders such as irritable bowel syndrome. Abundant preclinical evidence indicates that treatments targeting this system offer a promising approach for treating certain neuropsychiatric, as well as, other stress-related physical illnesses. Promoter Neuroscience (PNS) has developed intellectual property related to the promoter sequences of the CRF family of genes and is developing screening tools for drug discovery. PNS has demonstrated the feasibility of using cell cultures transiently transfected with CRF system promoter reporter constructs as high throughput screening tools. The proposed studies will further develop PNS's proprietary technologies and help accelerate the discovery of compounds capable of altering expression of the CRF system. To improve this technology and to make a drug-screening tool relevant to humans, we will transfer our technology to human cortical neuronal cultures, which are derived from a brain region that naturally expresses CRF receptors and has been implicated in mediating the psychopathology. One set of cells will be transfected with constructs containing the human CRF receptor 2a (CRF2a) promoter driving expression of the Lucifer's reporter gene. Separate cortical neuronal cultures will be stably transfected with constructs containing the luciferase reporter gene under control of the human CRF receptor 1 (CRF1) promoter. Studies will characterize the basal levels of expression from the stably transfected cultures. To begin to explore potential new therapeutic approaches, expression from the stably transfected cultures will be monitored following treatment with compounds known to activate several different intracellular pathways. Activation of these intracellular pathways will lead to stimulation of transcription factors that bind to putative cis-regulatory elements identified within the CRF1 and CRF2a promoter regions. The stably transfected human cortical neuronal cultures will provide models relevant to human brain function that will provide PNS with the potential to discover new drugs that regulate CRF receptor expression.